• Korean Journal of Community Nutrition
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• v.11 no.1
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• pp.14-24
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• 2006

The purpose of this study was to investigate the relation between bone mineral density and nutrient intake among normal and obese elementary students. Each subject was assigned to one of such as normal (n = 69) and obese groups (n = 94) according to their obesity indices. And they were asked for general characteristics, dietary habits and nutrient intakes using questionnaires and 24-hr recall method. They measured the sound of speed (SOS) of calcaneus using quantitative ultrasound. The averages age of the subjects were 10.6 years in normal and 10.7 years in obese group. The averages weight (p < 0.001) and obesity index (p < 0.001) of the normal group were significantly lower than those of the obese group. In dietary habits, the obese group in boys was the higher skipped breakfast than normal group (p < 0.01). The plant calcium intake of obesity in girls was lower than those of normal group (p < 0.05). The SOS in the calcaneus was 1697.6 m/s in the obese group and 1763.7 m/s in the normal group (p < 0.01). The SOS in the calcaneus was negatively correlated to weight (p < 0.01), obesity index (p < 0.001) and percent of body fat (p < 0.01). Also the SOS in the calcaneus was positively correlated plant calcium intake (p < 0.05). In conclusion, the excessive increase of weight and percent of body fat in elementary students appeared to have negative impact to bone health. And based on these results, further studies on the effects on bone mineral density of obese and nutrient intakes in needed for proper bone health.

• The Korean Journal of Applied Statistics
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• v.24 no.6
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• pp.987-994
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• 2011

From the point view of credit evaluation whose population is divided into the default and non-default state, two methods are considered to estimate conditional distribution functions: one is to estimate under the assumption that the data is followed the mixture normal distribution and the other is to use the kernel density estimation. The parameters of normal mixture are estimated using the EM algorithm. For the kernel density estimation, five kinds of well known kernel functions and four kinds of the bandwidths are explored. In addition, the corresponding ROC functions are obtained based on the estimated distribution functions. The goodness-of-fit of the estimated distribution functions are discussed and the performance of the ROC functions are compared. In this work, it is found that the kernel distribution functions shows better fit, and the ROC function obtained under the assumption of normal mixture shows better performance.

• The Korean Journal of Food And Nutrition
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• v.25 no.1
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• pp.156-162
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• 2012

The purpose of this study was to investigate the effect and correlation of anthropometric data, eating behaviors, and nutrient intake on the bone mineral density(BMD) of female college students. 349 female college students were surveyed and their age, height, and weight were an average of 20.5 years, 163.2 cm and 54.0 kg, respectively. Their average BMI was 20.2, with 66% falling in the normal range, 21.8% classified as underweight, 8.0% as overweight, and obese individuals comprised 3.4% of the sample by BMI classification. Calcaneal BMD was measured and the average T-score was 0.117. The results of BMD measurements were normal in 268 people(76.8%), osteopenia was found in 71 individuals(20.3%), and osteoporosis in 10(2.9%), respectively. There was a significant difference in bone mineral density according to height(p<0.05) and BMI (p<0.01). There were significant differences between BMD and eating behavior, regularity of eating behaviors(p<0.05), instant food intake(p<0.05), eating out(p<0.05) and nutritional supplement intake(p<0.05). In addition, normal the group with normal BMD had a more desirable eating behavior compared to the osteopenia and osteoporosis afflicted groups. BMD had a significant difference according to the nutrient intake of calcium(p<0.05), vitamin A(p<0.05), and vitamin C(p<0.05). In conclusion, BMD showed a good correlation with height(p<0.01), BMI(p<0.01), body composition including total body water(p<0.05), FFM(p<0.05), body protein(p<0.05) and intake of calcium(p<0.05), iron(p<0.05), vitamin A(p<0.05), and vitamin C(p<0.05). Therefore, an education plan and training on balanced diets proper body weight control, and desirable eating behaviors for female college students will be needed.

• Research in Community and Public Health Nursing
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• v.21 no.3
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• pp.333-340
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• 2010

Purpose: The purpose of this study was to examine the bone mineral density (BMD), body mass index (BMI), stress, and health promotion lifestyle of female college students and to assess relations among them. Methods: A total of 220 female college students were assessed through anthropometric measurements and bone mineral density test using quantitative ultrasound. In addition, the subjects were asked about stress and health promotion lifestyle with a self-rating questionnaire. Collected data were processed with the SPSS/WIN 12.0 program. Results: 1) Of the students, 67.8% had weight control experience. The percentage of the osteoporosis, osteopenia and normal groups were 2.8%, 53.5% and 43.8%, respectively, and the percentage of the underweight, normal and overweight groups according to BMI were 27.9%, 57.2% and 14.9%, respectively. 2) The levels of stress and health promotion lifestyle were 2.9 and 2.3, respectively. 3) There was a positive correlation between BMD and BMI (r=.196, p<.01). There was a negative correlation between stress and health promotion lifestyle (r=-.35, p<.01). 4) Weight control experience made negative effects on BMD and BMI. Conclusion: The findings of this study suggest the necessity of new health promotion programs to increase bone density of female college students. Stress management programs are also needed.

• Journal of Nutrition and Health
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• v.28 no.4
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• pp.282-290
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• 1995

Subcutaneous fat thickness of 74 young male was measured at six sites(biceps, triceps, subscapula, suprailiac, abdomen, thigh). The present study compared caliper with ultrasound measurements for the estimation of body fat. Caliper measurements subcutaneous at six sites had higher coefficient variation than did the ultrasound measures. Caliper measurements subcutaneous at six sites had higher ratio (caliper/ultrasound) than did the ultrasound measures. Compared to other body sites, the correlations between caliper and ultrasound measurements were high for the subscapula(r=0.7327), abdomen(r=0.7355) and thigh (r=0.7207) sites. the correlations between caliper and ultrasound measurements were high for the suprailiac(r=0.6616) site by lean group. the correlations between caliper and ultrasound measurements were high for the abdomen(r=0.7636) site by normal group. The correlations between caliper and ultrasound measurements were high for the subscapula (r=0.8959) and abdomen(r=0.8237) sites by obese group. Ultrasound measurement of biceps(r=-0.4459), abdomen9r=-0.4469), thigh(r=-0.4348) had the highest correlation with body density. Caliper measurement of triceps(r=-0.4017), subscapula(r=-0.4454), abdomen(r=-0.4293) had the highest correlation with body density. Ultasound measurements subcutaneous fat at lean group, obese group had higher coefficients of correlation with body density than did the caliper measurement. Caliper measurements subcutaneous fat at normal group had higher coefficients of correlation with body density than did the ultrasound measures. Ultrasound showed to be superior to the caliper technique in measuring subcutaneous fat of obese persons.

• Journal of the Korean Statistical Society
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• v.13 no.2
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• pp.87-106
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• 1984

It ${X_t}$ is a sequence of independent identically distributed normal random variables, then the conditional probability density of $X_1, X_2, \cdots, X_n$ given the first p+1 sample autocovariances converges to the maximum entropy probability density satisfying the corresponding covariance constraints as the length of the sample sequence tends to infinity. This establishes that the maximum entropy probability density and the associated Gaussian autoregressive process arise naturally as the answers of conditional limit problems.

• Korean Journal of Adult Nursing
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• v.18 no.5
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• pp.790-797
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• 2006

Purpose: The purpose of this study was to investigate bone density and risk factors related to osteopenia to unmarried young adult women. Methods: The subjects consisted of 125 female college students. SPSS 12.0 program was used for the data analysis with t-test, ${\chi}^2-test$. The BMD of the calcaneus and body mass index (BMI) were measured with peripheral dual energy X-ray absorptionmetry. Other physical characteristics were measured with a scale and questionnaires. Results: The general characteristics of these people showed that the average age was 22.1 years old and that the average BMI was 20.8. The mean of BMD was normal, but 24.8% were osteopenia, 75.2% were normal. In the normal and osteopenia groups, there were significant differences in the status of the BMD according to age, height, weight, BMI, regular exercise, house chores, and the experiences of being on a diet. Conclusion: Women in their twenties had some osteoporosis risk, but they can change their BMD by doing regular exercise and by eating food to peak bone mass. For building peak bone mass, they need take exercise programs and education programs to prevent osteoporosis and follow-up care.

• Biomedical Science Letters
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• v.17 no.2
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• pp.123-128
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• 2011

We analyzed the concentration of serum total cholesterol (TC), high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), triglyceride (TG) and the serum lipoprotein electrophoresis fractions in hypertensive patients (hypertension group, n=182). The average concentration of lipids and lipoprotein fractions in the hypertension group was compared to that of the normal group. The average concentrations of serum TC, LDLC and TG in the hypertension group were significantly higher than those of the normal group (3.3%, 11% and 70%, respectively) (P<0.05). But HDLC was nonsignificantly lower (2%) (P<0.05). In the hypertension group, the percentages of patients who had an abnormally high level of total cholesterol, HDLC, LDLC and TG were 12.1%, 8.2%, 24.2% and 44.5%, respectively. The average of ${\beta}$-lipoprotein (27.5%) and pre ${\beta}$-lipoprotein (12.6%) were significantly higher, whereas ${\alpha}$-lipoprotein (15.2%) was significantly lower in the hypertension group than in the normal group (P<0.05). The percentages of patients who had an abnormally high level of very low density lipoprotein (pre ${\beta}$-LP), LDLC (${\beta}$-LP) and chylomicron were 31.3%, 17.0% and 12.6%, respectively. This study suggests that an increasing of total cholesterol, LDLC and TG, pre ${\beta}$-LP, ${\beta}$-LP and chylomicron are associated with a risk factor for hypertension.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.286-293
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• 2010

Peak bone mass is established predominately during childhood and adolescence. It is an important determinant of future resistance to osteoporosis and fractures to gain bone mass during growth. The issue of low bone density in children and adolescents has recently attracted much attention and the use of pediatric dual-energy X-ray absorptiometry (DXA) is increasing. The process of interpretation of pediatric DXA results is different from that of adults because normal bone mineral density (BMD) of children varies by age, body size, pubertal stage, skeletal maturation, sex, and ethnicity. Thus, an appropriate normal BMD Z-score reference value with Z-score should be used to detect and manage low BMD. Z-scores below -2.0 are generally considered a low BMD to pediatrician even though diagnoses of osteoporosis in children and adolescents are usually only made in the presence of at least one fragility fracture. This article will review the basic knowledge and practical guidelines on pediatric DXA based on the International Society for Clinical Densitometry (ISCD) Pediatric Official Positions. Also discussed are the characteristics of normal Korean children and adolescents with respect to BMD development. The objective of this review is to help pediatricians to understand when DXA will be useful and how to interpret pediatric DXA reports in the clinical practice for management of children with the potential to develop osteoporosis in adulthood.

• The Korean Journal of Applied Statistics
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• v.27 no.3
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• pp.397-406
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• 2014

The minimum density power divergence estimation has been a popular topic in the field of robust estimation for since Basu et al. (1988). The minimum density power divergence estimator has strong robustness properties with the little loss in asymptotic efficiency relative to the maximum likelihood estimator under model conditions. However, a limitation in applying this estimation method is the algebraic difficulty on an integral involved in an estimation function. This paper considers a minimum density power divergence estimation method with approximated divergence avoiding such difficulty. As an example, we consider the normal-exponential convolution model introduced by Bolstad (2004). The estimated divergence in this case is too complicated; consequently, a Laplace approximation is employed to obtain a manageable form. Simulations and an empirical study show that the minimum density power divergence estimators based on an approximated estimated divergence for the normal-exponential model perform adequately in terms of bias and efficiency.